Diabetes mellitus during pregnancy

In the United States, the incidence of obesity among pregnant women ranges from 18.5 to 38.3% according to different reports and the rate of gestational diabetes mellitus (GDM) approaches 15%. There are three classifications of glucose intolerance in pregnancy: pre-existing type 1 diabetes, pre-existing type 2 diabetes and GDM. Type 1 diabetes is an autoimmune disease in which the pancreatic β-cells are destroyed. Type 2 diabetes is believed to be a combination of insulin resistance and relative insulin deficiency. Its etiology is traced to a strong genetic predisposition to insulin resistance further aggravated by obesity and diminished pancreatic β-cell function. In contrast, women who develop glucose intolerance at any time during pregnancy are classified as GDM. This chapter addresses issues concerning the epidemiology and diagnosis of GDM and the association between obesity, gestational diabetes and pregnancy outcome and further implications for adult life.